Wrist pin lock



March 19, 1935. P, J. MEEHAN 1,994,617

WRIST PIN LOCK Filed April 19, 1934 Inventor Attorney Patented Mar. 19, 1935 "t I I I a UNITED STATES PAT ENT OFFICE wlus'r PIN LOCK Philip J. Meehan, Philadelphia, Pa. Application April 19, 1934, Serial No. 721,393

3 Claims. (01. s-s.5)

This invention pertains to new and useful im- Figure 4 is a sectional view through the modprovements in wrist pin locks for pistons and ification, taken substantially on the line 44 of has for its primary object to provide, in a manner Fi ure 2. as hereinafter set forth, a locking ring embody- Referring now to the drawing in detail, it will 5 ing novel means for eliminating knocking be seen that the reference numeral 1 designates 5 caused by end float in pins of the full floating a conventional piston of the type in widespread type by suppressing and cushioning the end float use-at present in the internal combustion engines of the pin. of automobiles. The piston 1, as usual, is pro- Another important object of the invention is vided with bearings 2 in which the end por- 0 to provide a wrist pin lock of the character detions of a wrist pin 3 a e journaled. Adjace t scribed which may be conveniently installed in the ends of the Wr s p 3, e bearings 2 have conventional pistons of the type using full fioatformed therein circumferential grooves ing wri t in The lock constituting the present invention Other objects of the invention are to provide comprises a split, resilient, expansible ring O a wrist pin lock of the aforementioned character of which is engaged in each of the grooves 4, as 15 which will be comparatively simple in construcillustrated to advantage in Figure 1 0f e d wtion, strong, durable, highly efficient and reliable ing. Adjacent one end, the resilient ring 5 is in use, and which may be manufactured at low formed to provide an inwardly directed loop 6 cost. which terminates in a free end portion '7 engaged 0 Nine times out of ten, wrist pin knocks are with the adjacent end of the wrist pin 3 for yieldnot due to circumferential wear in either the ingly resisting suppressing and cushioning end wrist pin or its bushing, butare caused by end float of said wrist pin. 'I'heintersecting point float of the pin, against each of its retaining 8 of the loop 6 and the ring 5 is located just inlock wires. wardly of the inner periphery of the wrist pin 3.

The remedy for this was to dismantle the mo- Further, it will be noted that the loop 6 passes 25 tor and fit oversize wrist pins, which was an exthe inner side of the ring 5, thus bracing or suppensive procedure. Since the advent of alumporting the end portion 7 of the lock which eninum alloy pistons, even snugly fitted pins soon gages the wrist pin. u start to float and knock, due to heat expansion In the modified form of the invention illus- 0 of the wrist pin hole. The manufacturers protrated in Figures 2to 4, inclusive, of the drawing, videda plurality of oil holes to lubricate the the reference numeral 9 designates a resilient, movement of the floating pin in the piston, but. split, expansible ring which is formed to provide nothing to prevent the pin from knocking up a resilient loop 10. The loop 10, it will be noted, against its retaining lock wires. passes adjacent the outer side ofthe ring 9 and My improvement in these wrist pin lock wires terminates in an intumed end portion 11 which is 3 has dual purpose of providing a, substantial wrist engageable with the adjacent end of the wrist pin lock, and also to cushion and suppress the in. end float of the pin, so as to prevent knocking, It will thus be seen that a lock of comparatively a without interfering with the circumferential simple construction has been provided which will flo f t p Without c ange in design effectively suppress and cushion end float in pis- 40 of piston or pin or method of installation. ton wrist pins of the full floating type. As is l Of t e foregoing d St l u the Obje ts believed to be readily apparent, the locks may be and ad a a of the invention Will b o e pexpeditiously installed by simply contracting the Parent from a Study Of the following Specification, same by suitable means and inserting in the pistaken in nn cti n wi h e mpa ying ton bearings 2 and then releasing, permitting drawing wherein like characters of reference desthe rings to expand and seat in the grooves 4. ignate corresponding parts throughout the several It is believed that the many advantages of a views, and wherein:- wrist pin lock constructed in accordance with the Figure 1 is a view in side elevation of a piston, present invention will be readily understood, and

showing a wrist pin lock in accordance with the although preferred embodiments of the inven- 50 present invention installed therein. tion are as illustrated and described, it is to be Figure 2 is a view in side elevation of a slightly understood that further modifications and modified form of the'invention. changes in the details of construction may be Figure 3 is a view of the modification, taken resorted to which will fall within the scope of the at right angles to Figure 2. invention as claimed. j 55 What is claimed is: grooves, said ring including s resilient loop, said 1. Awrlst pin lock for pistons having wrist pin loop terminating in en sngulsrly extending i'ree bearings provided with annular grooves, comprisend portion engageable with the end ofthe wrist ing a. split, resilient ring engageable in the pin. 5 grooves, said ring including a resilient loop, said 3. A wrist pin lock of the class described comloop terminating in a free end portion engageprising a split, resilient ring, and a resilient loop able with the end 0! the wrist pin. on one end of the ring for suppressing and cush- 2. A wrist pin lock for pistons having wrist pin ioning end float of the wrist pin. bearings provided with annular grooves, com- 1o prising a split, resilient ring engageable in the PHILIP J. MEEHAN. 1 

